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Establishment of a metric to characterize retroreflector properties using a consumer-grade colour camera

Transportation Safety and Environment 2023年第1期5卷 31-40页

作者： huayang he Wenying Su Qiutong Cheng National Center of Metrization for Equipments of Roads and Bridges Research Institute of Highway Ministry of TransportBeijing 100088China Division of Optical Metrology National Institute of MetrologyBeijing 100029China

The coefficients of retroreflection and chromaticity coordinates are critical metrics for determining the quality of a ***,conventional retroreflection measurement techniques rely heavily on the night-time colour,size and characteristics of thesample being *** complicates the measurement process and leads to deviations in the test *** addition,chromaticitycannot be determined using this ***,it is necessary to improve the measurement accuracy,simplify themeasurement process and achieve themeasurement of the traffic sign RA and chromaticity coordinates *** this study,an improved method for retroreflector characterization using imaging was *** allowed for the measurement of the coefficientsof retroreflection and the chromaticity coordinates simultaneously,and only a white standard sample was required for *** primary components of the proposed system included a lighting projector,a receiver,two motorized rotational stages,a retroreflective sample holder and customized software that using scaling factors to convert a digital signal into sample retroreflectioncoefficients and retroreflective chromaticity *** experimental results indicated that the raw data output from thecamera exhibited a positive correlation relationship with the luminous flux from the surface of the *** maximummeasurementerrors for the retroreflection and chromaticity were−12.2 cd/(lx·m2)and−2.09%,*** was inexpensiveand convenient,used a commercially available digital camera,could help to identify defects in retroreflection and chromaticity forretroreflective sheeting and led to increased accessibility for the quality control of retroreflective sheeting.

关键词： camera chromaticity coordinates coefficient of retroreflection retroreflective sheeting retroreflector

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氧化钙固体碱催化剂用于大豆油和甲醇酯交换制备生物柴油的研究

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石油炼制与化工 2006年第12期37卷 39-43页

作者：刘学军贺华阳王玉军朱慎林清华大学化学工程系化学工程联合国家重点实验室北京100084

对氧化钙固体碱催化剂用于甲醇和大豆油的酯交换反应制备生物柴油(脂肪酸甲酯)进行了研究,考察了醇油摩尔比、反应温度、催化剂用量等因素对生物柴油产率的影响,以及采用四氢呋喃等溶剂溶解产物中的甘油和脂肪酸甲酯以分离回收催化剂的... 详细信息

对氧化钙固体碱催化剂用于甲醇和大豆油的酯交换反应制备生物柴油(脂肪酸甲酯)进行了研究,考察了醇油摩尔比、反应温度、催化剂用量等因素对生物柴油产率的影响,以及采用四氢呋喃等溶剂溶解产物中的甘油和脂肪酸甲酯以分离回收催化剂的方法。结果表明,在醇油摩尔比为12、反应温度为65℃、催化剂用量为8%、反应1．5h的条件下,生物柴油产率达到了95%以上。重复使用实验结果表明,CaO的催化活性比K_2CO_3/γ-Al_2O_3和KF/γ-Al_2O_3固体碱催化剂高,寿命更长,重复使用20次后催化效果无明显下降。

关键词：生物柴油甲醇大豆油催化剂氯化钙

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透射式能见度仪校准装置的研制及测量结果分析

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应用光学 2023年第6期44卷 1355-1361页

作者：李勍张瑛欣张帆台宏达何华阳李奕陕西省计量科学研究院国家市场监管总局重点实验室(计量光学及应用) 陕西西安710100 江苏省计量科学研究院长度计量研究所江苏南京210023 中国民航大学航空气象系天津300300 交通运输部公路科学研究院北京100088

为了解决国内外能见度参数量值无法绝对溯源的问题,利用透射式能见度仪的工作原理、结构特点以及环境条件,提出了溯源至几何量的量值复现方法,设计了1套高透射比量具作为主标准器,实现了对透射式能见度仪的校准,促进了能见度参数量值溯... 详细信息

为了解决国内外能见度参数量值无法绝对溯源的问题,利用透射式能见度仪的工作原理、结构特点以及环境条件,提出了溯源至几何量的量值复现方法,设计了1套高透射比量具作为主标准器,实现了对透射式能见度仪的校准,促进了能见度参数量值溯源体系的发展。主标准器遮光体采用精密机械加工工艺,遵循几何量参数测量的绝对溯源法,可大幅减小透射比量值的测量不确定度;主标准器滤光片根据几何量测量和光学透射比参数测量相结合的溯源链,解决了现有技术中高透射比无法复现和准确测量的问题。此外,使用锥形遮光体,可避免引入除旋转因素外的其他不确定度来源,大幅提升了能见度仪分辨率的校准能力。

关键词：能见度仪透射式能见度仪大气透过率校准系统

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基于车载LiDAR点云的道路提取方法

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光学技术 2023年第1期49卷 29-33页

作者：徐安帝王会峰余炳伟何华阳宋尚真长安大学电子与控制工程学院陕西西安710064 西安应用光学研究所第十七研究室陕西西安710065 交通运输部公路科学研究院北京100088

针对提取道路点云聚类方法存在欠分割、过分割的问题,提出了一种基于坡度滤波算法和改进欧式距离的区域生长算法相结合的道路点云提取方法。原始点云数据量大且繁杂,采用统计分析进行预处理,去除一定数量悬空的噪声,减少数据量;为防止... 详细信息

针对提取道路点云聚类方法存在欠分割、过分割的问题,提出了一种基于坡度滤波算法和改进欧式距离的区域生长算法相结合的道路点云提取方法。原始点云数据量大且繁杂,采用统计分析进行预处理,去除一定数量悬空的噪声,减少数据量;为防止点云数据精度损失,对预处理后的点云按照格网进行划分,结合坡度滤波算法,去除非地面点干扰,获取地面点云;以法向量夹角和欧氏距离为约束条件,采用改进的区域生长算法提取路面点云。使用两组不同场景下的车载点云数据进行试验,证明了该方法的有效性。

关键词：激光技术道路点云提取坡度滤波区域生长算法

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Variable strength combinatorial testing of concurrent programs

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Frontiers of Computer Science 2016年第4期10卷 631-643页

作者： Xiaofang QI Jun he Peng WANG huayang ZHOU School of Computer Science and Engineering Southeast University Nanjing 211189 China Key Laboratory of Computer Network and Information Integration Ministry of Education Southeast University Nanjing 211189 China NARI Relays Electric Cooperation Nanjing 211102 China

Reachability testing is an important approach to testing concurrent programs. It generates and exercises syn- chronization sequences automatically and on-the-fly without saving any test history. Existing reach, ability testing can be classified into exhaustive and t-way testing. Exhaustive testing is impractical in many cases whilie t-way testing may decrease the capability of fault detection in some cases. In this paper, we present a variable strengda reachability testing strategy, which adopts the dynamic framework of reachability testing and uses a variable strength combinatorial strategy. Different parameter groups are provided with different covering strength. Variable strength testing covers no t-way combinations but the necessary combinations of parameters having mutual interactions in a concurrent program. It is more reasonable than t-way testing because uniform interactions between parameters do not often exist in concurrent systems. We propose a merging algorithm that implements the variable strength combinatorial testing strategy and conduct our experiment on several concurrent programs. The experimental results indicate that our variable strength reachability testing reaches a good tradeoff between the effectiveness and efficiency. It can keep the same capability of fault detection as exhaustive reachability testing while substantially reducing the number of synchronization sequences and decreasing the execution time in most cases.

关键词： software testing variable strength combinatorial testing concurrency testing reachability testing

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逆反射测量仪陶瓷板反光特征的数值分析

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交通科技 2021年第6期31卷 110-114页

作者：冷正威薛瑛琪王蕊何华阳交通运输部公路科学研究院北京100088 国家道路与桥梁工程检测设备计量站北京100088

为解决标线逆反射测量仪所配套的工作标准器耐候性不佳问题,研究一种使用陶瓷标定板承载标定用逆反射亮度系数量值的工作标准器。然而,未探明反光特征等问题阻碍了此类工作标准器的应用。针对陶瓷标定板漫反射的特点,分析陶瓷标定板反... 详细信息

为解决标线逆反射测量仪所配套的工作标准器耐候性不佳问题,研究一种使用陶瓷标定板承载标定用逆反射亮度系数量值的工作标准器。然而,未探明反光特征等问题阻碍了此类工作标准器的应用。针对陶瓷标定板漫反射的特点,分析陶瓷标定板反光的一般规律,建立反光强度的数学模型,采用控制变量法对陶瓷标定板反光强度与入射角、观测距离、观测位置的关系进行研究。结果表明,陶瓷标定板表面的反光强度随观测位置的变化呈非球面分布。使用陶瓷标定板对便携式逆反射标线测量仪进行标定时,其入射角度宜接近0°,且观测距离宜小于1 m。

关键词：逆反射亮度系数逆反射测量仪陶瓷标定板反光特征数值分析

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Fault-Tolerant Scheduling for Real-Time Embedded Control Systems

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Journal of Computer Science & Technology 2004年第2期19卷 191-202页

作者： Chun-huayang GeertDeconinck Wei-HuaGui CollegeofInformationScience&Engineering CentralSouthUniversityChangsha410083P.R.China ElectricalEngineeringDepartment KatholiekeUniversiteitLeuvenKasteelparkArenberg10B-3001Leuven-HeverleeBelgium

With the increasing complexity of industrial application, an embedded control system (ECS) requires processing a number of hard real-time tasks and needs fault-tolerance to assure high reliability. Considering the characteristics of real-time tasks in ECS, an integrated algorithm is proposed to schedule real-time tasks and to guarantee that all real-time tasks are completed before their deadlines even in the presence of faults. Based on the nonpreemptive critical-section protocol (NCSP), this paper analyzes the blocking time introduced by resource conflicts of relevancy tasks in fault-tolerant multiprocessor systems. An extended schedulability condition is presented to check the assignment feasibility of a given task to a processor. A primary/backup approach and on-line replacement of failed processors are used to tolerate processor failures. The analysis reveals that the integrated algorithm bounds the blocking time, requires limited overhead on the number of processors, and still assures good processor utilization. This is also demonstrated by simulation results. Both analysis and simulation show the effectiveness of the proposed algorithm in ECS.

关键词： embedded control system real-time task scheduling fault-tolerance relevancy task blocking time

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Synthesis and Characterization of Chitosan-g-poly- (D, L-lactic acid) Copolymer

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Chinese Chemical Letters 2005年第1期16卷 123-126页

作者： huayang ShaoBingZHOU XianMoDENG ChengduInstituteofOrganicChemistry ChineseAcademyofSciences.Chengdu610041

Biodegradable chitosan-g-poly (D, L-lactic acid) copolymers were prepared via two methods. (1) The lactide was grafted onto hydroxyl groups of chitosan by using macromolecular initiator sodium of trimethylsilyl-chitosan, (2) poly (D,L-lactic acid)(PLA) with low molecular weight can be linked to the amino group by coupling activated PLA to trimethylsilyl-chitosan. Two graft copolymers had hydrophilic-hydrophobic character and can be applied as carriers for drug delivery.

关键词： Poly (D L-lactic acid) chitosan graft copolymer coupling macromolecular initiator.

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Analysis of ground deformation development and settlement prediction by air-boosted vacuum preloading

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第1期14卷 272-288页

作者： Shuangxi Feng huayang Lei Cheng Lin Department of Civil Engineering Tianjin UniversityTianjin300354China Key Laboratory of Coast Civil Structure Safety of the Ministry of Education Tianjin UniversityTianjin300354China Key Laboratory of Comprehensive Simulation of Engineering Earthquake and Urban-Rural Seismic Resilience China Earthquak AdministrationTianjin300354China Department of Civil Engineering University of VictoriaVictoriaBCV8P 5C2Canada

Vacuum preloading has been widely used to improve soft soils in coastal areas of *** increasing amount of evidence from field operations has shown that conventional vacuum preloading is prone to clogging in prefabricated vertical drains(PVDs)and demands a large volume of sand *** recent years,air-boosted vacuum preloading has been developed to overcome these limitations;however,this method still requires more data to verify its *** this study,a field test for air-boosted vacuum preloading was conducted,and a large-strain two-dimensional(2D)finite element(FE)model was developed and validated against the field test ***,a series of FE parametric analyses was performed to assess key factors,*** air injection pressure,the injection spacing,and the characteristics of cyclic injection,which affect the performance of the air-boosted vacuum *** results showed that the ground settlement and lateral displacement of the soils increased due to an increase in the injection pressure,a decrease in the injection spacing,or increases in the number and duration of the injection *** on the parametric analyses,an empirical formula for ground settlement prediction was proposed and compared with a case history reported in the literature,showing good agreement.

关键词： Air-boosted vacuum preloading Field test Numerical modeling Settlement Soft soils Ground improvement

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Ground movements modeling applying adjusted influence function

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International Journal of Mining Science and Technology 2020年第2期30卷 243-249页

作者： Agnieszka Malinowska Ryszard hejmanowski huayang Dai AGH University of Science and Technology Al.Mickiewicza 3030059 KrakowPoland China University of Mining and Technology BeijingD11 Xueyuan Road100083 BeijingChina

Mathematical modeling of surface deformations caused by underground mining operation is commonly carried out with use of empirical,numerical or stochastic *** of the most frequently applied model for prediction of ground deformation in many countries is Knothe *** model developed by Knothe belongs to the stochastic methods and is based on the influence *** China a prediction method named Probability Integration Method(PIF)was established by Liu Baochen and Liao Guohua based on the stochastic medium *** version of that model allows to predict ground movements caused by mining operation in extremely complex technical and geological *** model is commonly applied for coal,metal ore and salt *** article presents several modifications of the mathematical model used in China and *** model is very widespread in the world,therefore the generalizations proposed in the article can be implemented for the purposes of prediction surface deformations for various types of deposits in many *** presented generalizations were then tested on specific examples of coal mining,copper ore mining and rock salt *** obtained results indicate high efficiency of methods based on the influence function in complex geological and mining conditions.

关键词： Mining operation Modeling of surface deformations Stochastic models Probability integration method Influence function Salt hard coal mining copper ore mining

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